Departments

Theoretical Physics in Sheffield

Research Groups

Polymers and Soft Matter
We study, using analytical theory, computational methods and simulations a wide variety of
phenomena that occur in polymers and other soft materials. Current projects are focussed on
instabilities and pattern formation in thin films of mixtures driven by coupling between
thermodynamics and kinetics, current/voltage characteristics in organic photovoltaics, templating
nanoparticle self-assembly with block copolymers, and the anomolous dynamics of polymers in the
presence of nanoparticles. Previous projects include mechanical properties of organogels and actin
networks, blood flow through vein valves, phase separation and microstructure evolution in polymer
blends and the coupling between phase transitions and flow. For more information, contact
Nigel Clarke.

Biophysics
Working with experimental physicists and biologists in Sheffield and elsewhere, we use analytical
theory and computation to model biological systems. Our aim is to construct simple models that
capture the physical mechanisms involved. In particular we focus on the cell cytoskeleton, which is
made up of protein filaments (actin, microtubules) and molecular motors. These biopolymers form a
viscoelastic gel that is out of equilibrium due to the consumption of biochemical energy and is an
example of what is known as an active gel. We are interested in how the properties of this material
enable cells to carry out biological processes such as polarisation, migration, adhesion and
endocytosis. For more information, contact
Rhoda Hawkins.

Theory of Photonic Crystals and Microcavities
Most of the theoretical work in the group is concerned with the study of photonic crystals and
planar semiconductor microcavities. We are currently developing an approach to calculating
properties of photonic crystals based on Wannier functions from electronic structure theory. The
main aim is to design high finesse optical cavities for studying cavity quantum electrodynamics
and quantum information processing. Another major topic is understanding the properties of the
Optical Parametric Oscillator (OPO) which is observed in resonantly pumped planar microcavity
structures. Other interests include surface states on photonic crystals, THz emitters, and excitonic
states in low dimensional structures. We also have strong links with the quantum dot work in the
Department of Electronic & Electrical Engineering. For more information, contact
David Whittaker.

Optical Quantum Information Processing
The research in this group focusses mainly on quantum information processing with optical systems.
This encompasses how to build a quantum computer and quantum communication devices using
light, quantum information extraction via metrology, and reseach in quantum imaging and lithography.
In addition, we are interested in relativistic extensions of quantum information theory, in
particular how quantum communication channel capacities are affected by curved spacetime. For more
information, contact Pieter Kok.

Theoretical Magnetism
Research in theoretical
magnetism supports the programme in experimental magnetism.
Current topics include developing an understanding of the origins of magneto-optic properties of
magnetic oxides and the behaviour of multiferroic manganites and also pseudo spin models for phase
transitions in other materials, for example in liquid crystals. A computational study is underway
on the properties of ferromagnetic nanoparticles embedded in a weakly magnetic oxide. A new
project is available to expand on this topic to include the electron transport and hence to
calculate magnetoresistance for granular materials and also tunnelling magnetoresistance between
two such materials. The group works closely with collaborators in Russia, China and the UK (York).
For more information please contact Gillian Gehring.

Theoretical astrophysics
As part of the astronomy group we study the formation and dynamical
evolution of stars and star clusters. We are interested the
hydrodynamics of star formation, especially multiple star formation,
and the evolution of (planet-forming) discs in binary stars. We also
study the pure gravitational phases of star cluster formation and
binary destruction. We also investigate the statistical properties of
both binary and multiple stars, and the distributions of young stellar
systems. For more information contact Simon Goodwin

Quantum Dynamics
The research in this group focusses on the theoretical/computational study of
chemical reactions using quantum dynamics. The systems studied vary from small
fundamental gas-phase reactions, like H + O$_2$, an important combustion
reaction to gas-surface reactions involving small molecules in the
interstellar medium. The results of our calculations are compared to the
results of sophisticated experiments performed by collaborators to obtain
insight into the fundamentals of the reactions involved. Since our
calculations are very time-consuming, we are also heavily involved in the
development of new computational algorithms with a particular emphasis on
parallellizability. For more information, contact Anthony Meijer.